Set Layer

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare destructiveHint=true and idempotentHint=true, and the description adds genuine context: partial updates, the cross-layer side effect that solid_color/solid_size alter the solid item for every layer using it, and that audio_fade works under duck_music. It doesn't explain reversibility or why the call is flagged destructive.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Dense but efficient: every clause explains a distinct non-obvious field with no filler, which is proportionate to a 30-parameter tool. The telegraphic semifcolon stream is hard to scan and doesn't group related fields, but nothing is wasted.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 30-parameter mutation tool with no output schema, the description covers the tricky flags but omits semantics for a substantial set of parameters (timing fields, three_d, adjustment, time_remap, preserve_transparency) and says nothing about permissions, failure modes, or effects on linked properties.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

With 0% schema coverage across 30 parameters, the description carries the full burden, and it only explains roughly half (stretch, parent_id, blend_mode, auto_orient, collapse, guide, sampling, solid_*, audio_fade, separate_dimensions). Non-obvious fields such as in/out units, start, time_remap, three_d, adjustment, and preserve_transparency are left undefined.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

"Edit a layer; only the fields you pass change" gives a specific verb, resource, and patch semantics that distinguish it from add_layer/delete_layer. It doesn't explicitly compare itself to other property-setting siblings like set_property or set_comp, but the scope is unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The patch-semantics line tells the agent it can send a single field without clobbering others, and it flags a real prerequisite: motion_blur/frame_blending require the switch in set_comp too. It stops short of stating when to prefer set_property over set_layer or any ordering/precondition rules.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.